Process of producing metallic relief-plates for pictorially burning or searing wood



(1% J. W.'ROBBINS. PROGBSS 0P PRODUGING MBTALLIG RRLIRR PLATES FORPIGTORIALLY BURNING 0R SHARING WOOD. No. 475,047. Patented May 17, 1892.

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UNITED STATES PATENT OFFICE.

JOHN W. ROBBINS, OF BOSTON, MASSACHUSETTS.

PROCESS OF PRODUCING METALLIC RELIEF-PLATES FOR PICTORIALLY BURNING ORSEARING WOOD.

SPECIFICATION forming part of Letters Patent N 0. 475,047, dated May 17,1892.

' Application filed January 21, 1891. Serial No. 378,534. (No model.)

To all whom it may concern.-

Be it known that I, J OHN W. ROBBINS, of Boston, in the county ofSulfolk and State of Massachusetts, have invented a new and usefulImprovement in Etching Metal Plates, of which the following is aspecification.

Pictures or drawings belonging to the class known as poker pictures areproduced by searing wood with hot irons.

My improvement consists of a process of etching a metal plate so thatafter this plate has been heated and applied to a surface of wood forthe purpose of burning into or searing the same an efiect of gradationof light and shade and variety of textureis produced; and my inventionalso consists in a plate adapted to be heated and provided with reliefor raised lines and surfaces of varying height.

To carry my invention into effect I first make a drawing on a plate ofsteel, copper, brass, German silver, or other suitable metal. What areintended to be the darkest portions in the reproductionsviz., in thewood surface-are in this metal surface stopped out that is, covered withvarnish or shellac. The rest of the surface of the plate is then loweredby being eaten away with acid, or, if necessary, grinding. In order toproduce a number of gradations of light and shade, therefore, the plateis bitten by the acid several times-that is to say,'after stopping out(with varnish or shellac) the part of the plate which is to produce thedeepest shadow in the reproduction and lowering the rest of the surfaceby acid, as above mentioned, then the parts which are to produce thenext darkest shadein the reproduction are covered With varnish and theplate bitten again. This is repeated until all the desired gradationshave been obtained. After this plate is heated it is obvious that whenit is placed against a wooden surface the highest part of the plate willburn the deepest into the wood, the next highest part will burn lessdeeply, and the next still less deeply, each part producing anappearance more or less dark, according to its relative height.

In the accompanying drawings, in which similar letters of referenceindicate like parts, Figure 1 is a plan view of a plate produced by myprocess. Fig. 2 is a section on line A B, Fig. 1.

The parts a of the plate are the highest portions and were stopped outat the beginning of the process, having received no acid, and hence,when applied to a wooden surface, burn the deepest and produce thedarkest shade. The parts I) have been bitten once by the acid and werethen stopped out and produce the next darkest shade. The parts 0 havebeen bitten twice and produce a still lighter shade. The part d has beenbitten three times, and the part e has been bitten four times andproduces the lightest shade, while the part f has been bitten fiye timesby the acid, and when the metal plate is pressing against the woodensurface this part does not come in contact with the wood, and hence doesnot burn it at all, but. leaves the surface white or in its naturalcolor. During this process the texture of foliage, gravel, grass,cobbles, &c., is produced by a manipulation of stopping-out varnish orshellac on the metal while it is being bitten by the acid. This plate,after being etched in the above-described manner, may be used to producean indefinite number of pictures or decorations on wood, the effectbeing the same as in what are known as poker pictures or drawings madeby searing Wood with hot irons. It is particularly adapted for interiordecoration and furniture embellishment.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

1. The process of producing metallic reliefplatesfor pictorially searingor burning Wood, consisting in first reducing portions of the surface ofthe plate to leave irregularlines or surfaces in one plane and thenfurther reducing portions of the surface first reduced to leaveirregular lines or surfaces of a height varyingfrom those firstproduced, substantially as described.

2. A metallic plate adapted to be heated and provided with pictorialrelief'or raised lines and surfaces of varying heights, the lines whichare in the same plane being irregular, substantially as described.

JOHN W. ROBBINS.

\Vitnesses:

HENRY W. WILLIAMS, 4 J. M. HARTNETT.

